Why does EF6 CodeFirst many-to-many conflict with ForeignKey?

Question

ASP.NET

I have two classes like this, ef doesn't want to create a many-to-many table, when I add the Client_Id field, it will add the Class_ID to the Client table, but if I remove the Curator_Id field, then many-to-many is created... What's the problem ?

public class Class
    {
        public int ID { get; set; }

        public Class()
        {
            this.Members = new HashSet<Client>();
        }

        public virtual ICollection<Client> Members { get; set; }

        [ForeignKey("Client_Id")]
        public virtual Client Client { get; set; }
        public virtual string Client_Id { get; set; }
}

public class Client
 {
 public Client()
        {
            this.Classes = new HashSet<Class>();
        }
public string Id {get; set;}
public virtual ICollection<Class> Classes { get; set; }
}

Answer 1

It is better to use the Fluent API Relationships between models in the Fluent API
You, as I understand it, want to have both a Client list and another Client list in the "Event" which is the curator. You need to poke it, some things EF cannot do either in one migration, or at all.